Mite composition comprising Glycyphagidae and phytoseiid mites, use thereof, method for rearing a phytoseiid predatory mite, rearing system for rearing said phytoseiid predatory mite and methods for biological pest control on a crop

ABSTRACT

The present invention relates to a novel mite composition comprising a population of a phytoseiid predatory mite species and a factitious host population comprising a species selected from the Glycyphagidae, which may be employed for rearing said phytoseiid predatory mite species or for releasing the phytoseiid predatory mite species in a crop. According to further aspects the invention relates to a method for rearing a phytoseiid predatory mite species, to the use of the mite composition and to a method for biological pest control in a crop, which employ the mite composition.

This invention according to a first aspect relates to a novel mitecomposition comprising at least one species from the Glycyphagidae andat least one phytoseiid mite species.

According to a second aspect the invention relates to a novel method forrearing a phytoseiid predatory mite species.

According to a third aspect the invention relates to a novel use of anAstigmatid mite species selected from the family of the Glycyphagidae asa factitious host, for rearing a phytoseiid predatory mite species.

According to a fourth aspect the invention relates to a novel rearingsystem for rearing a phytoseiid predatory mite species. According to afifth aspect the invention relates to the use of the mite composition orthe rearing system for the control of crop pests.

According to yet further aspects the invention relates to a method forbiological pest control in a crop employing the mite compositionaccording to the invention.

In the following description and claims the names of the phytoseiid mitesubfamilies, genera and species is as referred to in de Moraes, G. J. etal., 2004, unless otherwise stated. In the following description andclaims the names of the Glycyphagidae subfamilies, genera and species isas referred to in Hughes, A. M., 1977, unless otherwise stated. Anoverview of the referenced families, subfamilies, genera and species isprovided in FIGS. 1 and 2.

Phytoseiid predatory mites (Phytoseiidae) are widely used for biologicalcontrol of spider mites and thrips in greenhouse crops. The mostimportant thrips species in greenhouse crops are Western Flower Thrips(Frankliniella occidentalis) and Onion Thrips (Thrips tabaci). They canbe controlled with the predatory mites Neoseiulus cucumeris andNeoseiulus barkeri (Hansen, L. S. and Geyti, J., 1985; Ramakers, P. M.J. and van Lieburg, M. J., 1982; Ramakers, P. M. J., 1989; Sampson, C.,1998; and Jacobson, R. J., 1995) and Iphiseius degenerans (Ramakers, P.M. J. and Voet, S. J. P., 1996). In the absence of prey these speciesare able to establish, develop and maintain in crops which provide acontinuous supply of pollen, such as sweet peppers (Capsicum annuum L.)and eggplants (Solanum melogena). Therefore they can be releasedpreventively in these crops, before the suitable target pest prey ispresent. Also they are able to survive and continue to develop once thetarget pest has been controlled. The possibility for preventive releasesis very important in order to obtain a robust biological controlprogram. Excellent results are obtained with preventive release ofpredatory mites (because the prey can be controlled immediately when itenters the crop). In crops where pollen is not freely available, such asfor example cucumbers and most ornamental crops, these phytoseiid mitespecies cannot be released preventively unless food is artificiallyprovided. This can e.g. be done by dusting artificially collected plantpollen on the crop.

Alternatively, or in addition to this, this could also be done byreleasing the target pest prey before or together with releasing thephytoseiid predatory mites. This method, known as pest-in-first,involves obvious risks of introducing the pest and requires a lot ofexperience. The best known example of pest-in-first is the release oftwo-spotted spider mites (Tetranychus urticae) together or prior to therelease of the phytoseiid mite Phytoseiulus persimilis.

In the case of Neoseiulus cucumeris alternatively a controlled releaserearing system (as disclosed by Sampson, C. (1998) or in GB2393890) canbe used for preventive release of this phytoseiid mite species. Thiscontrolled release rearing system consists of a sachet with acompartment which contains a food mixture, consisting of bran, yeast andwheat germ; a population of the grain mite Tyrophagus putrescentiae anda population of the predatory mite Neoseiulus cucumeris. The grain miteTyrophagus putrescentiae will reproduce and develop an active populationon the food mixture and serves as a factitious host for the predatorymite population. The sachets are hung in the crop with suitable means,e.g. by means of a hook and will continuously release predatory mitesover a period of 4 to 6 weeks.

In crops which provide a continuous supply of pollen or in case pestpopulations are already present, a slow-release sachet is not needed andthe product can be applied on the crop as a loose material, comprisingof suitable rearing medium with a population of the grain miteTyrophagus putrescentiae and the phytoseiid Neoseiulus cucumeris.

Because Neoseiulus cucumeris has a rather weak numerical response to thepresence of food, large quantities of predatory mites have to bereleased into a crop in order to have sufficient pest control. This iseconomically possible because Neoseiulus cucumeris can be economicallyreared in very large quantities on the grain mite Tyrophagusputrescentiae, which may be reared in sufficient amounts on the abovedescribed food mixture.

Although there are much more efficient predatory mites for thripscontrol with a higher predation rate and numerical response, such asTyphlodromalus limonicus and Iphiseius degenerans, Neoseiulus cucumerisis still the most commonly used species because it can easily be rearedin very large quantities.

Iphiseius degenerans is mass-reared on Castor Bean Plants (Ricinuscommunis L., Euphorbiaceae) which provide a continuous supply of pollenon which the mites can develop large populations. Because of the largesurface and high investment in greenhouses needed for growing the plantsand because of the laborious harvesting techniques, the cost price ofIphiseius degerenans is very high compared to Neoseiulus cucumeris. Dueto this high cost price growers can only release very low numbers,typically 1000-2000 predatory mites per hectare. Therefore, theapplication of Iphiseius degenerans is limited to peppers (Capsicumannuum L.), which provide sufficient pollen on which the predatory mitescan develop a population, which is sufficient for pest control. Becauseonly small numbers of mites can be released at the beginning of thegrowing season, it takes several months before the population ofIphiseius degenerans is at sufficient strength in a crop in order to beable to have a significant impact on Thrips pest populations.

Two-spotted Spider Mites (Tetranychus urticae) are successfullycontrolled in greenhouse and outdoor crops world-wide by releasingpredatory mites. The most important species are Phytoseiulus persimilis(Hussey, N. W. and Scopes, N. E. A., 1985), which is the oldest mitewhich is commercially available for biological control and Neoseiuluscalifornicus (Wei-Lan Ma and Laing, J. E., 1973). Both predatory mitesare mass-reared on their natural host Tetranychus urticae on bean plants(Phaseolus vulgaris) in greenhouses. Castagnoli, M. and Simoni, S.(1999) have also described a method for mass-rearing Neoseiuluscalifornicus on the House Dust Mite Dermatophagoides farinae. However,House Dust Mites (Dermatophagoides farinae and Dermatophagoidespteronyssinus) produce important allergens, implicated in allergicasthma, rhinitis, conjunctivitis and dermatitis. Therefore their use incontrolled release rearing systems for releasing predatory mites incrops has disadvantages. Another disadvantage is that when House DustMites are used for mass-rearing purposes, extensive measures arenecessary for worker protection. Scientific literature reports manypredatory mites which are highly effective against damaging crop pestspecies such as white flies, thrips, spider mites, tarsonemid mites anderiophyid mites, but, due to the absence of an efficient andcost-effective mass-rearing system, only a few species are commerciallyavailable for biological pest control purposes.

Recent research has indicated the potential of the predatory mitesAmblyselus swirskii, Euseius ovalis, Euseius scutalis and Typhlodromaluslimonicus as very efficient biological control agents of thrips (Thripstabaci and Frankliniella occidentalis) and whiteflies (Trialeurodesvaporariorum and Bemisia tabaci) (Nomikou, M., Janssen, A., Schraag, R.and Sabelis, M. W., 2001; Messelink, G. & Steenpaal, S. 2003; Messelink,G. 2004; Messelink, G. & Steenpaal, S. 2004; Bolckmans, K. & Moerman, M.2004; Messelink, G. & Pijnakker, J. 2004; Teich, Y. 1966; Swirski, E. etal., 1967). However, the practical usability of these and otherphytoseiid predatory mites as an augmentative biological control agentdepends on the availability of a suitable method for mass-rearing therepredatory mites.

To date only Amblyseius swirskii is commercially available forbiological control of whiteflies. Recently this phytoseiid mite wasintroduced to the market by Koppert B. V. Commercial market introductionof Amblyseius swirskii was possible due to the development of acommercially feasible method for mass-rearing this predatory mite, whichinvolves the use of Carpoglyphus lactis as a factitious host. Thismethod is part of the subject matter of the pending non-prepublishedinternational application NL2004/000930.

The reason, that only recently a predatory mite, which preys on whiteflies, has become commercially available, is probably because despitethe known predation of predatory mites on whiteflies their usability asaugmentative biological control agents against whiteflies has not beenrecognized in the art. In augmentative biological control, biologicalagents are released in a crop for the control of a pest.

Even more important, with the exception of the recently developedrearing system for Amblyseius swirskii, no economic mass-rearingsystems, necessary for allowing the release of large numbers ofpredatory mites into a crop, which is of utmost importance for theirusability as an augmentative biological control agent, are available inthe art for predatory mite species, e.g. those which could potentiallybe efficacious against whiteflies or other crop pests.

Biological control of crop pests with predatory mites which can beeconomically reared in large quantities on a factitious host mite in arearing medium would be very advantageous because such a rearing systemuses a limited surface. Furthermore in such a system rearing of thepredatory mite can be performed in controlled climate rooms. As such itdoes not require large investments in greenhouses and crops.

The prior art describes rearing of Neoseiulus cucumeris and Neoseiulusbarkeri with the aid of a factitious host mite species from the genusTyrophagus, in particular Tyrophagus putrescentiae, Tyrophagus tropicus,Tyrophagus casei (Sampson, C., 1998; Jacobson, R. J., 1995; Bennison, J.A. and R. Jacobson, 1991; Karg et al., 1987; and GB293890) and from thegenus Acarus, in particular Acarus siro (Beglyarov et al., 1990) andAcarus farris (Hansen, L. S. and J. Geyti, 1985; Ramakers, P. M. J. andvan Lieburg, M. J., 1982), which all belong to the family of theAcaridea.

The most common rearing host for Neoseiulus cucumeris is Tyrophagusputrescentiae. An important disadvantage of Tyrophagus putrescentiae isthat it can cause plant damage to young plant leaves when it is presenton crops, e.g. when used as a factitious host in slow release breedingsachets similar to that disclosed by (Sampson, C., 1998) or in GB293890.This is especially the case in cucumber crops during periods of highhumidity especially if this is combined with a low light intensity.

Castagnoli et al. have also described the possibility of mass-rearingNeoseiulus californicus (Castagnoli, M. and S. Simoni, 1999) andNeoseiulus cucumeris (Castagnoli, M., 1989) on the House Dust MiteDermatophagoides farinae as a factitious rearing host. However, HouseDust Mites (Dermatophagoides farinae and Dermatophagoides pteronyssinus)produce important allergens, implicated in allergic asthma, rhinitis,conjunctivitis and dermatitis.

Therefore the traditional method for mass-rearing Neoseiuluscalifornicus is on bean plants (Phaseolus vulgaris) infested withtwo-spotted spider mites (Tetranychus urticae) or pacific mites(Tetranychus pacificus) in greenhouses which results in a rather highcost price. Due to the cost price of mites which are reared in thissystem, only relatively low numbers can be released to control pests ina crop. Development of a mas-rearing method with a factitious host whichcan be reared on a suitable medium would result in a much lower costprice and therefore allow the release of much higher numbers asbiocontrol agents in crops. The factious hosts, which are known in theprior art, such as Tyrophagus spp., Acarus spp. are only suitable formass-rearing a limited number of phytoseiid mite species. For examplethe phytoseiid mites N. californicus and N. fallacis cannot be rearedefficiently on Tyrophagus putrescentiae and Acarus siro.

Thus there is a need in the art for additional factitious hosts whichcan be used for mass rearing beneficial mites, such as predatory mites.Especially for rearing of Amblyseius swirskii, Neoseiulus fallacis,Neoseiulus californicus, Typhlodromips montdorensis, Neoseiuluswomersleyi, Euseius ovalis or Euseius scutalis. For many phytoseiidpredatory mite species only rearing on plant pollen has been disclosedin literature.

Rearing on pollen necessitates either large greenhouse areas for theproduction of plants such as Castor Bean Plants (Ricinus communis) toobtain sufficient pollen, or collecting suitable plant pollen such asfrom Cattail (Typha spp.) or Oak (Quercus spp.) outdoors. Collectingplant pollen outdoors is very labour intensive and therefore expensiveand only limited quantities can be collected. Honeybee collected plantpollen is unsuitable for rearing predatory mites.

For A. swirskii mite rearing has only been disclosed in the art usingpollen (Messelink, G. & Pijnakker, J. 2004) or eggs from thelepidopterans Corcyra cephalonica or Ephestia kuehniella (Romeih, A. H.M. et al., 2004).

Rearing on lepidopteran eggs requires large investments in productionfacilities and thus is very expensive. Also, rearing on lepidopteraneggs is not suitable for several mite species such as for exampleNeoseiulus californicus and Neoseiulus fallacis.

In addition to this mass-rearing of Amblyseius swirskii on thefactitious host Carpoglyphus lactis is now known. In order to fullycomply with the demands of the market, additional factitious hosts arenecessary.

SUMMARY OF THE INVENTION

It has now been found that Astigmatid mite species from the family ofthe Glycyphagidae may be used as a factitious host for a great number ofphytoseiid predatory mite species.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a list of Glycyphagidae species and their genus name.

FIG. 2 provides a list of Phtoseiid species and their genus name.

DETAILED DESCRIPTION

Thus according to a first aspect the invention relates to a mitecomposition comprising a rearing population of a phytoseiid predatorymite species and a factitious host population comprising at least onespecies selected from the family of the Glycyphagidae.

The mite composition according to the invention preferably comprises alimited number of different species. It will be understood that the mitecomposition will comprise at least two distict species, the phytoseiidmite and the factitious host selected from the Glycyphagidae. It ishowever possible that the mite composition comprises more than twospecies e.g. by comprising more than one, such as two or threefactitious host species or by comprising more that one, such as two orthree, phytoseiid mite species. It is however less preferred that themite composition comprises more that one phytoseiid mite species, asintraguild predation may occur.

The phytoseiid predatory mite species which are most likely to be ableto feed on species selected from the Glycyphagidae and in particularLepidoglyphus destructor or Glycyphagus domesticus are oligophagousphytoseiid predatory mite species. An oligophagous phytoseiid predatorymite species is a phytoseiid predatory mite species which is able to useat least a few different prey species as a food source for itspopulation development (reproduction and complete development of itsindividuals from egg to sexually mature adult). As such the termoligophagous predatory mite species in this specification includes apolyphagous mite species, being a predatory mite which can use a greatnumber of prey species as a food source for its reproduction andcomplete development. Thus the term oligophagous predatory mite speciesis to be understood to mean a non-monophagous predatory mite speciessuch as predatory mite species from the genus Phytoseiulus which have avery narrow host range which is mostly limited to the genus Tetranychus.

Factitious host species and factitious prey species are species whichinhabit a different natural habitat then the phytoseiid predatory mite,but nevertheless one or more life stages of the factitious host orfactitious prey are suitable prey for at least one life stage of thephytoseiid predatory mite. Because factitious hosts and factitious preysinhabit a different natural habitat than phytoseiid predatory mites,whose natural habitat is the phyllosphere of plants, phytoseiidsnormally do not feed on them in nature. The phytoseiid predatory mitehas the ability to reproduce and develop efficiently from egg tosexually mature adult when feeding upon a diet of the factitious hostsuch that the number of individuals in the rearing population of thephytoseiid mite can grow with at least 50%, preferably 75%, morepreferably 100% in 7 days (T=25° C.; RH=80% feeding ad libidum).

In contrast to this, a factitious prey is a prey on which a phytoseiidmite species may be able to prey, however development of egg to sexuallymature adult is not efficient. A very low fecundity and high mortalityis observed during development from egg to adult, resulting in apopulation increase of less than 50% in 7 days under mass-rearingconditions. As such, when feeding on a diet consisting solely of afactitious prey, a rearing population of a phytoseiid predatory mitewill not be able to increase the number of its individuals by at least50%, in 7 days time (T=25° C.; RH=80%, feeding ad libidum), which isconsidered a minimum requirement for commercial mass-rearing.

Phytoseiid predatory mites have their natural habitat on plants wherethey prey on pest organisms (insects and mites). They may be isolatedfrom their natural habitats as described by de Moraes et al., 2004.

Glycyphagidae are described by Hughes, A. M. (1977). Based on thedisclosure of this document the skilled person will be able to isolatespecific species from this family from their natural habitat. Asdescribed by Hughes, A. M. (1977) Glycyphagidae are associated withinsects or small mammals or nests of small mammals and social insectssuch as bees. They are typically associated with houses, stables andwith storage or processing of dried food products such as granaries andflour mills. In houses they can be found in materials such as floordust, damp and mouldy wall paper, felt, dried animal skins, storage ofstored food products and in upholstery made from processed plant fibres.In animal stables they can be found in materials such as hay, straw,floor dust, dried animal food (pellets or flour), stored grains andpoultry droppings. Typical stored food products on which Glycyphagidaecan be found are flour, grains, cereals, cheese, ham, dried fish, driedyeast, seeds and dried fruit.

Thus the composition according to the invention provides a newassociation of mites, which does not occur naturally, as the phytoseiidpredatory mites inhabit a different habitat than the Glycyphagidae.

Dyadechko, N. P. and Chizhik, R. I. (1972) disclose experiments whereinTyphlodromus aberrans (currently known as Campynodromus aberrans(Oudemans 1930)) is collected in felt bands during Autumn with the goalto release them in other orchards in the next spring. Apart fromTyphlodromus aberrans, the spider mite Tetranychus telarius iscollected. Predation of Typhlodromus aberrans on Tetranychus telarius isdescribed. It is described that after fully having eradicated the spidermite Tetranychus telarius from the felt bands Typhlodromus aberrans fedon a non-specified species of Glycyphagus which was present in the feltbands. No information is given about reproduction of T. aberrans on theunspecified Glycyphagus species, only about predation.

The composition according to the invention is not only suitable formass-rearing of a phytoseiid predatory mite. As it also comprises mobilepreying life stages of a phytoseiid predatory mite, or life stages whichcan develop into these mobile life stages, it can also be employed as abiological crop protection agent.

In a preferred embodiment the composition comprises a carrier for theindividuals of the populations. The carrier can be any solid materialwhich is suitable to provide a carrier surface to the individuals.Preferably the carrier provides a porous medium, which allows exchangesof metabolic gases and heat produced by the mite populations. Examplesof suitable carriers are plant materials such as (wheat) bran, buckwheathusks, rice husks, saw dust, corn cob grits etcetera.

It is further preferred if a food substance suitable for the developmentof the factitious host population is added to the composition.Alternatively the carrier itself may comprise a suitable food substance.A suitable food substance may be similar to that described by Parkinson,C. L., 1992; Solomon, M. E. & Cunnington, A. M., 1963; Chmielewski, W,1971a; Chmielewski, W, 1971b or GB2393890.

According to a preferred embodiment of the composition the phytoseiidpredatory mite is selected from:

-   -   the subfamily of the Amblyseiinae, such as from the Genus        Amblyseius, e.g. Amblyseius andersoni, Amblyseius swirskii or        Amblyseius largoensis, from the genus Euseius e.g. Euseius        finlandicus, Euseius hibisci, Euseius ovalis, Euseius        victoriensis, Euseius stipulatus, Euseius scutalis, Euseius        tularensis, Euseius addoensis, Euseius concordis, Euseius ho or        Euseius citri, from the genus Neoseiulus e.g. Neoseiulus        barkeri, Neoseiulus californicus, Neoseiulus cucumeris,        Neoseiulus longispinosus, Neoseiulus womersleyi, Neoseiulus        idaeus, Neoseiulus anonymus or Neoseiulus fallacis, from the        genus Typhlodromalus e.g. Typhlodromalus limonicus,        Typhlodromalus aripo or Typhlodromalus peregrinus from the genus        Typhlodromips e.g. Typhlodromips montdorensis;    -   the subfamily of the Typhlodrominae, such as from the genus        Galendromus e.g. Galendromus occidentalis, from the genus        Typhlodromus e.g. Typhlodromus pyri, Typhlodromus doreenae or        Typhlodromus athiasae. These phytoseiid predatory mite species        may be considered as being oligophagous predatory mite species.

The phytoseiid predatory mite according to a preferred embodiment of theinvention is selected from the subfamily Amblyseiinae as described by DeMoraes et al., 2004. In a further preferred embodiment the phytoseiidpredatory mite is selected as Amblyselus swirskii, Neoseiulus fallacis,Neoseiulus californicus, Typhlodromips montdorensis, Neoseiuluswomersleyi, Euseius ovalis or Euseius scutalis. For these specieseconomic mass-rearing on a factitious host mite has not been disclosedin the art, with the exception of A. swirskii and N. californicus.

Mass-rearing of Neoseiulus californicus on Dermatophagoides farinae hasbeen described in the art (Castagnoli, M. and Simoni, S. (1999)) asdiscussed above. However, this is associated with problems relating tothe allergens carried by Dermatophagoidea. Mass-rearing of this specieson Tetranychus urticae or Tetranychus pacificus on bean plants(Phaseolus vulgaris) in greenhouses or outdoors has also been describedin the art (Hendrickson, R. M., Jr., (1980); Glasshouse Crops ResearchInstitute, UK. (1976)), as discussed above. However, this is associatedwith high investments in greenhouses and high input of labour, materialand energy.

Commercial mass-rearing of Amblyseius swirskii has only been publiclydisclosed with the use of the factitious host Carpoglyphus lactis as afactitious host. It will be beneficial to provide additional factitioushosts for the mass-rearing of this predatory mite.

For Typhlodronmips montdorensis, Neoseiulus womersleyi, Euseius ovalisand Euseius scutalis laboratory-scale rearing on plant pollen has beendisclosed. However, commercial mass-rearing on pollen is expensive andthus not economically favourable.

Neoseiulus fallacis is commercially available. However, this predatorymite is mass-reared on its natural prey, which involves largeinvestments.

The present invention now for the first time discloses a mitecomposition, comprising a species from the family of the Glycyphagidaeas a factitious host, which can be used for economic rearing of theseand other phytoseiid predatory mite species. Making it possible to usethem as an augmentative biological pest control agent.

It should however be understood that in certain embodiments of theinvention the phytoseiid predatory mite species is selected from aspecies other than those, which are particularly preferred.

Differences in acceptance of the factitious host may be observed betweendifferent strains of the phytoseiid predatory mite species. Furthermore,it might be possible to breed a strain, which is adapted to a specificfactitious host by selective breeding.

In this specification the term rearing must be understood to include thepropagation and increase of a population by means of sexualreproduction.

A rearing population may comprise sexually mature adults from bothsexes, and/or individuals of both sexes of other life stages, e.g. eggsand/or nymphs, which can mature to sexually mature adults. Alternativethe rearing population may comprise one or more fertilized females. Inessence the rearing population is capable of increasing the number ofits individuals by means of sexual reproduction.

Preferably the factitious host population is a rearing population, asdefined above, such that it may sustain or even develop itself to acertain degree. If the factitious host is provided as a rearingpopulation, preferably a food substance for the factitious host is alsoprovided. The food substance may be similar to a food substance asdisclosed in Solomon, M. E. and Cunnington, A. M., 1963; Parkinson, C.L., 1992; Ramakers, P. M. J. and van Lieburg, M. J., 1982; GB2393890.The factitious host is preferably selected from the subfamilyCtenoglyphinae, such as from the genus Diamesoglyphus e.g. D.intermedius or from the genus Ctenoglyphus, e.g. C. plumiger, C.canestrinii, C. palmifer; the subfamily Glycyphaginae, such as from thegenus Blomia, e.g. B. freemani or from the genus Glycyphagus, e.g. G.ornatus, G. bicaudatus, G. privatus, G. domesticus, or from the genusLepidoglyphus e.g. L. michaeli, L. fustifer, L. destructor, or from thegenus Austroglycyphagus, e.g. A. geniculatus; from the subfamilyAëroglyphinae, such as from the genus Aëroglyphus, e.g. A. robustus;from the subfamily Labidophorinae, such as from the genus Gohieria, e.g.G. fusca; or from the subfamily Nycteriglyphinae such as from the genusCoproglyphus, e.g. C. Stammeri, and more preferably is selected from thesubfamily Glycyphaginae, more preferably from the genus Glycyphagus orthe genus Lepidoglyphus most preferably selected from G. domesticus orL. destructor. Contrary to Tyrophagus putrescentiae, for theGlycyphagidae and in particular Lepidoglyphus destructor and Glycyphagusdomesticus no damage to crops has been observed in comparative fieldtrials. Therefore, a factitious host from this selection will havebenefits when the composition according to the invention is used forcrop protection in such a way that individuals of the factitious hostpopulation may come in contact with the crop e.g. when applied directlyon or in the vicinity of the crop or when used inslow/controlled/sustained release sachets.

A further benefit of the Glycyphagidae and particularly of Lepidoglyphusdestructor and Glycyphagus domesticus is that they are considered to becosmopolitan species. As such international trade of products comprisingone of them will encounter less regulatory restrictions as isencountered in many countries for foreign species.

A further benefit of the Glycyphagidae and in particular Lepidoglyphusdestructor and Glycyphagus domesticus is that they can be used tocommercially mass-rear certain phytoseiid predatory mite species whichcannot be reared on Tyrophagus spp. or Acarus spp., such as Neoseiulusfallacis and Neoseiulus californicus.

Also it has been found that Lepidoglyphus destructor and Glycyphagusdomesticus are in particular suitable factitious hosts for Neoseiuluscalifornicus and for Neoseiulus fallacis as these predators can feed onmultiple life stages and under certain circumstances all life stages ofthese hosts.

In the composition the number of individuals of the phytoseiid predatorymite species relative to the number of individuals of the factitioushost may be from about 1000:1 to 1:20, such as about 100:1 to 1:20 e.g.1:1 to 1:10, preferably about 1:4, 1:5 or 1:7.

The relative numbers may depend on the specific intended use of thecomposition and/or the stage of development of phytoseiid mitepopulation on the factitious host. In general compositions whereinindividuals of the factitious host are present in excess to theindividuals of the phytoseiid mite are preferred for rearing of thephytoseiid mite species, so that sufficient prey is provided to thephytoseiid mite. However, as the phytoseiid mite population willincrease while preying on the factitious host, the relative number ofindividuals of the phytoseiid mite species will increase.

A composition comprising a high relative number of the phytoseiidpredatory mite may be formed from a composition comprising a smallerrelative number and allowing the rearing population of the phytoseiidpredatory mite to develop by preying on the factitious host.Alternatively a composition comprising a small relative number of thephytoseiid predatory mite can be formed by mixing a compositioncomprising a higher relative number with a composition comprising asmaller relative number, including a composition comprising solely thefactitious host, optionally in combination with the carrier and/or afood substance suitable for the factitious host.

According to a preferred embodiment the mite composition comprises afurther nutritional source for the phytoseiid mite. The term nutritionalsource should be understood to comprise any source of material that mayserve as nutrition for the phytoseliid mite. Such a nutritional sourcemay comprise an artificial diet, such as described in U.S. Pat. No.6,129,935. However, as a nutritional source plant pollen or a prey arepreferred. The prey may comprise a factitious host such as a speciesselected from the family of the Carpoglyphidae such as from the genusCarpoglyphus, preferably the species Carpoglyphus lactis or from otherfamilies or genera belonging to the Astigmata. By presenting anadditional nutritional source, the phytoseiid mite is presented with amore diverse diet. It has been observed that combination of nutritionalsources may lead to synergetic effects with respect to the predator'sresponses in terms of growth and/or reproduction.

According to a further aspect the present invention relates to a methodfor rearing the phytoseiid predatory mite species. The method comprisesproviding a composition according to the invention and allowingindividuals of said phytoseiid predatory mite to prey on individuals ofsaid factitious host population.

For an optimal development of the phytoseiid predatory mite, thecomposition is e.g. maintained at 18-35° C., preferably 20-30° C., morepreferably 20-25° C., most preferably 22-25° C. Suitable relativehumidity ranges are between 60-95%, preferably 70-90%. These temperatureand relative humidity intervals are in general also suitable to maintainthe factitious host species. It is preferred that the compositioncomprises a carrier which can provide a porous medium and a foodsubstance for the factitious host species, and that the factitious hostspecies is maintained as a three dimensional culture on the carrier. Insuch a three dimensional culture members of the factitious host speciesare free to move in three dimensions. In this way they may infest alarger volume of the carrier and utilise the food substance moreoptimally. Considering the size of the mobile stages of the phytoseiidpredatory mite species relative to individuals of the factitious host,this organism will in general also infest the total volume of thecarrier, when foraging for the factitious host. Preferably the threedimensional culture is obtained by providing the carrier in a threedimensional layer, i.e. a layer having three dimensions, of which twodimensions are larger then one dimension. Exemplary is a horizontallayer with a length and breadth in the order of meters and a certainthickness in the order of centimeters. A three dimensional layer ispreferred because it will allow sufficient exchange of metabolic heatand gasses and will provide a larger production volume compared to a twodimensional layer.

According to a further aspect the invention is aimed to the use of anAstigmatid mite selected from the family of the Glycyphagidae as afactitious host for rearing a phytoseiid predatory mite.

The Astigmatid mite is preferably selected from the subfamilyCtenoglyphinae, such as from the genus Diamesoglyphus e.g. D.intermedius or from the genus Ctenoglyphus, e.g. C. plumiger, C.canestrinii, C. palmifer; the subfamily Glycyphaginae, such as from thegenus Blomia, e.g. B. freemani or from the genus Glycyphagus, e.g. G.ornatus, G. bicaudatus, G. privatus, G. domesticus, or from the genusLepidoglyphus e.g. L. michaeli, L. fustifer, L. destructor, or from thegenus Austroglycyphagus, e.g. A. geniculatus; from the subfamilyAëroglyphinae, such as from the genus Aëroglyphus, e.g. A. robustus;from the subfamily Labidophorinae, such as from the genus Gohieria, e.g.G. fusca; or from the subfamily Nycteriglyphinae such as from the genusCoproglyphus, e.g. C. Stammeri, and more preferably is selected from thesubfamily Glycyphaginae, and preferably is selected from the genusGlycyphagus or the genus Lepidoglyphus, most preferably selected from G.domesticus or L. destructor.

The phytoseiid predatory mite is preferably selected from:

-   -   the subfamily of the Amblyseiinae, such as from the Genus        Amblyseius, e.g. Amblyseius andersoni, Amblyseius swirskii,        Amblyseius largoensis or Neoseiulus fallacis, from the genus        Euseius e.g. Euseius finlandicus, Euseius hibisci, Euseius        ovalis, Euseius victoriensis, Euseius stipulatus, Euseius        scutalis, Euseius tularensis, Euseius addoensis, Euseius        concordis, Euseius ho, or Euseius citri, from the genus        Neoseiulus e.g. Neoseiulus barkeri, Neoseiulus californicus,        Neoseiulus cucumeris, Neoseiulus longispinosus, Neoseiulus        womersleyi, Neoseiulus idaeus, Neoseiulus anonymus or Neoseiulus        fallacis, from the genus Typhlodromalus e.g. Typhlodromalus        limonicus, Typhlodromalus aripo or Typhlodromalus peregrinus        from the genus Typhlodromips e.g. Typhlodromips montdorensis;    -   the subfamily of the Typhlodrominae, such as from the genus        Galendromus e.g. Galendromus occidentalis, from the genus        Typhlodromus e.g. Typhlodromus pyri, Typhlodromus doreenae or        Typhlodromus athiasae.

A selection from the subfamily of the Amblyseiinae is preferred.

According to a further aspect the invention relates to a rearing systemfor rearing the phytoseiid predatory mite.

The rearing system comprises a container holding the compositionaccording to the invention. The container may be of any type which issuitable for restraining individuals of both populations. The rearingsystem may comprise means which facilitate exchange of metabolic gasesand heat between it's interior and it's exterior such as ventilationholes. Such ventilation holes must not allow the substantial escape ofindividuals of the populations from the container. This can be effectedby creating a barrier on or around the ventilation holes which preventsthe substantial escape of mites from the container while facilitatingexchange of gases and metabolic heat.

Due to predation of the phytoseiid predatory mites the number ofindividuals of the factitious host in the composition will decrease. Ifnecessary, the factitious host may be replenished from a sourcecomprising the factitious host, preferably together with the carrierand/or food substance for the factitious host.

The rearing system may be suitable for mass-rearing the phytoseiid mitespecies. Alternatively the rearing system may also be used for releasingthe phytoseiid predatory mite in a crop. In this case it is preferredthat the container can be rendered suitable to release mobile stages ofthe phytoseiid predatory mite at a certain moment. This can be effectedby providing a closed opening in the container which can be opened.Alternatively or in combination therewith a relatively small releasingopening may be provided in the container, such that the number ofphytoseiid mobile stages which leave the container in a given timeinterval is restricted. In this way the rearing system may functionsimilar to the slow release or sustained release system as disclosed bySampson, C., 1998 and in GB2393890.

In such a rearing system for releasing the phytoseiid predatory mite ina crop the container is preferably dimensioned such that it can be hungin the crop or placed at the basis of the crop. For hanging in the cropthe container may be provided with hanging means, such as a cord or ahook.

According to a further aspect the invention is aimed at the use of thecomposition or the rearing system for controlling crop pests in acommercial crop.

Depending on the species of phytoseiid mite they can be used to controldifferent pest species. The pest may be selected from, white flies, suchas Trialeurodes vaporariorum or Bemisia tabaci; thrips, such as Thripstabaci or Frankliniella spp., such as Frankliniella occidentalis; spidermites such as Tetranychus urticae or Panonychus spp.; tarsonemid mitessuch as Polyphagotarsonemus latus; eriophyid mites such as the tomatorusset mite Aculops lycopersici; mealybug crawlers such as from theCitrus Mealybug Planococcus citri; scale crawlers such as from theCalifornia Red Scale Aonidiella aurantii.

The phytoseiid predatory mites Amblyseius swirskii, Euseius ovalis andEuseius scutalis have shown a good efficacy for controlling whitefliesand thrips. In the case of Neoseiulus californicus, Neoseiulus fallacis,Neoseiulus womersleyi the preferred target pests are spider mitesbelonging to the genus Tetranychus and Panonychus, tarsonemid mites suchas the Broad Mite Polyphagotarsonemus latus and the Cyclamen MiteTarsonemus pallidus. In the case of Neoseiulus womersleyi good efficacyhas been shown against thrips such as Franliniella occidentalis andagainst eriophyid mites such as the Tomato Russet Mite Aculopslycopersici.

The crop may be selected from, but is not restricted to (greenhouse)vegetable crops such as tomatoes (Lycopersicon esculentum), peppers(Capsicum annuum), eggplants (Solanum melogena), Curcubits(Cucurbitaceae) such as cucumbers (Cucumis sativa), melons (Cucumismelo), watermelons (Citrullus lanatus); soft fruit (such as strawberries(Fragaria x ananassa), raspberries (Rubus ideaus)), (greenhouse)ornamental crops (such as roses, gerberas, chrysanthemums), tree cropssuch as Citrus spp., almonds, banana's or open field crops such ascotton, corn.

The invention further relates to a method for biological pest control ina crop comprising providing a composition according to the invention tosaid crop.

The pest may be selected similarly as in the use according to theinvention.

In the method according to the invention the composition may be providedby applying an amount of said composition in the vicinity, such as on orat the basis of a number of crop plants. The composition may be providedto the crop plant simply by spreading it on the crop plant or at thebasis of the crop plant as is common practice for employing predatorymite compositions for augmentative biological pest control. The amountof the composition which may be provided to each individual crop plantby way of spreading may range from 1-20 ml such as 1-10 ml, preferably2-5 ml when applying at the basis of the crop plants and 0.1-5 ml whenapplying on the leaf canopy of the plants.

Alternatively the composition may be provided to the number of cropplants in the rearing system according to the invention which issuitable for releasing the phytoseiid predatory mite in a crop. Therearing system may be placed in the vicinity, such as in or at thebasis, of a number of crop plants.

In the method for biological pest control according to the invention itmay not be necessary to provide the composition to all crop plants. Ascommercial crops are normally densely cultivated. The phytoseiidpredatory mites may spread from one crop plant to another. The number ofcrop plants which must be provided with the composition according to theinvention in order to provide sufficient crop protection may depend onthe specific circumstances and can be easily determined by the skilledperson based on his experience in the field. Usually the number ofphytoseiid predatory mites released per hectare is more determining.This number may range from 1000-4 million per hectare, typically100.000-1 million or 50.000-500.000 per hectare. These numbers may bereleased once or multiple times per growing season, depending onclimatic conditions, pest pressure and usage of harmful pesticides.

In a further preferred embodiment of the method for biological pestcontrol according to the invention the crop is selected as described inrelation to the use of the composition.

The invention will now be further described with reference to thefollowing examples, which show non-limiting embodiments of differentaspects of the invention.

Experiment 1 Oviposition Test of N. fallacis on L. destructor.

Material and Methods

At the beginning of the experiment the N. fallacis adults were takenfrom an N. fallacis mass-culture on the food source L. destructor, whichwas started a few weeks earlier. 20 young adult females and 8 males werepicked up from this mass-culture and transferred to four freshlyprepared rearing containers. 5 females and 2 males of N. fallacis wereplaced in each one. In all of them as a food source was placed an ampleamount of L. destructor.

Once the four test cultures were prepared, they were located in aclimate room under controlled temperature (25° C.) and humidity (75%)conditions. After two or three days in these conditions, they were takenout. Four new rearing containers, similar to the previous ones, wereprepared to transfer the same 5 females and 2 males previously used.

Ample amount of L. destructor as a food source were added to each testculture as in the previous step. After transferring the males andfemales, the number of eggs was counted in the rearing containers fromwhich they were transferred.

The old rearing systems were conserved in the climate room during two orthree days for a second counting in order to detect some possible hiddenoffspring, after which they were destroyed. Similar to the old rearingsystems, the new ones were also maintained to repeat the same procedure.Every day the residual amount of L. destructor in each rearing containerwas checked. If necessary a sufficient amount was added.

Every two or three days data were obtained by evaluating the number ofoffsprings of both the new rearing (first counting) and the old one(second counting). Based on the number of females and on the totalamount of offspring which was found on each rearing container, the meannumber of eggs laid per female per day was obtained.

Results

When comparing the evolution of the number of eggs laid per femaleduring the total experiment (making one counting assessment each 2-3days), the mean ranges from 1.80 to 2.63 eggs/female/day.

For the whole period, the general mean is 2.14 eggs per female per day.The total amount of eggs laid per female is about 23 over a 11 daysperiod. Comparing the mean number of eggs laid per female per day forthe first, second, third and fourth independent rearing container, theseare 2.07, 2.09, 2.42 and 2.00, respectively. The experimental data ispresented in table 1 below.

TABLE 1 Food source: all stages of L. destructor. Data of the meannumber of eggs laid per N. fallacis female per day for the 4 independentrearing systems and for the global experiment. Total egg/day/ Mean Exp.Day Females offspring female eggs/day/female 1 2 5 18 1.80 2.07 4 5 202.00 7 5 29 1.93 9 5 24 2.40 11 5 22 2.20 2 2 5 19 1.90 2.09 4 5 18 1.807 5 32 2.13 9 5 25 2.50 11 5 21 2.10 3 2 5 18 1.80 2.42 4 5 23 2.30 7 534 2.27 9 5 31 3.10 11 4 21 2.63 4 2 5 18 1.80 2.00 4 5 18 1.80 7 5 332.20 9 5 23 2.30 11 5 19 1.90 eggs/day/ Mean day Period FemalesOffspring female eggs/day/females 2 0-2 days 20 73 1.83 2.14 4 3-4 days20 79 1.98 7 5-7 days 20 128 2.13 9 8-9 days 20 103 2.58 11 10-11 days19 83 2.18Experiment 2: Ovipostion Test of N. californicus on L. destructor

In essence similar to the method described in experiment 1 ovipositiontest were performed for N. fallacis.

These experiments differed as follows:

-   -   Instead of 4 subexperiments with 5 female A. fallacis, 4        subexperiments with 4 female N. californicus were conducted.    -   The testing period with N. californicus was 14 days in stead of        11 days.        Results

When comparing the evolution of the number of eggs laid per femaleduring the total experiment (making one counting assessment each 2-3days), the mean ranges from 1.25 to 3.33 eggs/female/day.

For the whole period, the general mean is 2.27 eggs per female per day.The total amount of eggs laid per female is about 31 over a 14 daysperiod. Comparing the mean number of eggs laid per female per day forthe first, second, third and fourth independent rearing container, theseare 2.50, 2.44, 2.49 and 1.70, respectively. The experimental data ispresented in table 2 below.

TABLE 2 Food source: all stages of L. destructor. Data of the meannumber of eggs laid per N. californicus female per day for the 4independent rearing systems and for the global experiment. Totalegg/day/ Mean Exp. Day Females offspring female eggs/day/female 1 2 4 232.88 2.50 5 4 35 2.92 7 4 18 2.25 9 4 19 2.38 12 4 25 2.08 14 4 20 2.502 2 4 21 2.63 2.44 5 4 29 2.42 7 4 20 2.50 9 4 15 1.88 12 4 29 2.42 14 317 2.83 3 2 4 20 2.50 2.49 5 3 30 3.33 7 3 14 2.33 9 3 15 2.50 12 3 161.78 14 3 15 2.50 4 2 4 14 1.75 1.70 5 4 25 2.08 7 4 13 1.63 9 4 14 1.7512 4 15 1.25 14 4 14 1.75 eggs/day/ Mean day Period Females Offspringfemale eggs/day/females 2 0-2 days 16 78 2.44 2.27 5 3-5 days 15 1192.64 7 6-7 days 15 65 2.17 9 8-9 days 15 63 2.10 12 10-12 days 15 851.89 14 13-14 days 14 66 2.36Biological Parameters of N. californicus in the First 3 Generation andafter Adaptation on Lepidoglyphus destructor

Experimental Procedures—

N. californicus was collected from mass rearing on Quercus spp. pollenmaintained at about 25° C., RH>80% and 16L: 8D. The experiment wasperformed at the same conditions. The rearing units (RU) were a plasticarena (diameter about cm 4.5), surrounded by wetted cotton and partiallycovered. Young ovipositing females of N. californicus were put in the RUand fed with L. destructor. The prey (all stages) was added to arenas insuch a way as to daily maintain an amount of prey higher than thephytoseiid consumption.

The eggs of N. californicus oviposited in the first 2 days were removed.The egg laid the successive two days were daily collected; some of themwere placed on new RU in small groups to calculate mortality and sexratio, the others were singly isolated to calculate development timesand egg-to-egg-time. From the progeny newly virgin females were confinedwith a mature male and the each couple daily followed for then day toregister oviposition and female longevity on the period.

The coeval eggs obtained were collected and used to start the secondgeneration on L. destructor: the procedure used for the first generationwas repeated for the second and third generation.

The performance of N. californicus on L. destructor was evaluated on thefirst-third generations and on an adapted strain (more than one year andhalf feeding on L. destructor)

TABLE 3 Biological parameters of N. californicus on L. destructor (25°C. ± 2° C., RH >80%, photoperiod 16L: 8D) generations 1st 2nd 3th Nthegg-to-egg time  8.6 ± 0.96 a  9.9 ± 1.27 b  9.5 ± 1.20 b  8.6 ± 1.10 a(days) n = 36 n = 25 n = 33 n = 34 juvenile mortality (%)  0.39 a  0.65a  1.60 a  1.67 a n = 259 n = 159 n = 187 n = 180 sex ratio (females %)66.67 a 63.64 a 58.70 ab 55.37 b n = 258 n = 154 n = 184 n = 177 escaperate (%) 13.71 21.43 25.51 30.32 n = 300 n = 197 n = 250 n = 254eggs/female/day 2.29 ± 0.0.43 a 2.03 ± 0.45 b 2.75 ± 0.49 c 2.15 ± 0.50ab (10 day period) n = 33 n = 32 n = 31 n = 26Demographic Parameters of N. californicus on L. destructor

Data obtained on L. destructor were used to calculate r_(g) and r_(m).The values obtained were summarized in the Table 4.

TABLE 4 Net reproductive rate (r_(g)) and estimate intrinsic growth rate(r_(m)) of N. californicus on L. destructor in the different generationat 25° C. and RH ≧80% r_(g) calculated (day⁻¹) r_(m) estimated (day⁻¹)1st generation 0.222 0.244 2nd generation 0.205 0.225 3th generation0.199 0.218 nth generation 0.203 0.223

REFERENCES

-   Athias-Henriot, C. (1962) Amblyseius swirskii, un nouveau    phytoseiide voisin d'A. andersoni (Acariens anactinotriches).    Annales de l'Ecole Nationale d'Agriculture d'Alger, Algeria, 3, 1-7.-   Beglyarov et al., 1990, Flour mite for mass breeding of phytoseiids,    Zashchita-Rastenii, no. 10, pp 25. Bennison, J. A. and Jacobson, R.,    1991, Integrated control of Frankliniella occidentalis (Pergande) in    UK cucumber crops—evaluation of a controlled release system of    introducing Amblyseius cucumeris, Med. Fac. Landbouww. Rijksuniv.    Gent, 56/2a, pp 251-255.-   Bolckmans, K. & Moerman, M. 2004, Nieuwe roofmijt verandert    bestrijding in paprika. Groenten & Fruit 41: 24-25-   Castagnoli, M., 1989, Biologia e prospettive di allevamento massale    di Amblyseius cucumeris (Oud.) (Acarina: Pyroglyphidae) com preda.-   Castagnoli, M. and Simoni, S., 1999, Effect of long-term feeding    history on functional and numerical response of Neoseiulus    californicus (Acari: Phytoseiidae), Experimental & Applied    Acarology, 23, pp 217-234.-   Castagnoli M., Simoni S., Biliotti N., 1999, Mass-rearing of    Amblyseius californicus on two alternative food source—In: J.    Bruin, L. P. S. van der Geest and M. W. Sabelis (eds), Ecology and    Evolution of the Acari, Kluwer Acad, Publ., Dordrecht, The    Nederlands, pp. 425-431.-   Chant, D. A., and J. A., McMurtry, 2004, A review of the subfamily    Amblyseiinae Muma (Acari: Phytoseiidae): Part III. The tribe    Amblyseiini wainstein, subtribe Amblyseiina N. subtribe.    Internat. J. Acarol., vol. 30, Nr. 3, p. 171-228.-   Chmielewski, W., 1971(a), Wyniki badan morfologicznych,    biologicznych i ekologicznych nad roztoczkiem suszowym, Carpoglyphus    lactis (L.) (The results of investigations on the morphology,    biology and ecology of the dried-fruit mite, Carpoglyphus lactis    (L.)), Prace-Naukowe-Instytutu-Ochrony-Roslin. 1971, publ. 1972, 13:    1, 87-106.-   Chmielewski, W., 1971(b), Morfologia, biologia i ekologia    Carpoglyphus lactis (L., 1758) (Glycyphagidae, Acarina) (The    morphology, biology and ecology of Carpoglyphus lactis (L., 1758)    (Glycyphagidae, Acarina)), Prace-Naukowe-Instytutu-Ochrony-Roslin.    1971, publ. 1972, 13: 2, 63-166.-   De Moraes, G. J., McMurtry, J. A., Denmark, H. A. & Cameos, C.    B., 2004. A revised catalog of the mite family Phytoseiidae.    Magnolia Press Auckland New Zealand 494 pp.-   Dyadechko, N. P. & Chizhik, 1972 (On the multiplication of    yphlodromus) (in Russian). Zashch. Rast. 17(2):22.-   Glasshouse Crops Research Institute, UK. 1976, Biological Pest    Control. Rearing parasites and predators. Grow. Bull. Glasshouse    Crops Res. Inst.: 23 pp.-   Hansen, L. S. and Geyti. J., 1985, Possibilities and limitation of    the use of Amblyseius McKenziei Sch. & Pr. for biological control of    thrips (Thrips tabaci Lind.) On glasshouse corps of cucumber,    Department of Zoology, Danish Research Centre for Plant Protection,    Lyngby, Denmark, pp 145-150.-   Hendrickson, R. M., Jr., 1980, Continuous production of predacious    mites in the greenhouse. J.N.Y. Entomol. Soc. 88(4): 252-256.-   Hughes, A. M., 1977, The mites of stored food and houses. Ministry    of Agriculture, Fisheries and Food, Technical Bulletin No. 9: pp    133-186-   Hussey, N. W. and N. E. A. Scopes, 1985, Biological Pest Control:    the Glasshouse Experience. Poole, UK.: Blandford Press (Ithaca,    N.Y.: Cornell University Press)-   Jacobson, R. J., 1995, Integrated pest management in    cucumbers—prevention of establishment of Frankliniella occidentalis    (Pergande), Med. Fac. Landbouww. Univ. Gent, 60/3a, pp 857-863.-   Karg et al., 1987, Advantages of oligophagous predatory mites for    biological control, Institute of Plant Protection Klenmachnow, pp    66-73.-   Karg et al., 1989, Fortschritte bei der Anwendung von Raubmilben zur    biologischen Schädlingsbekämpfung in Gewächshäusern, Gartenbau, 36,    pp 44-46.-   Karg, W., 1989, Die ökologische Differenzierung der Faubmilbarten    der Überfamilie Phytoseiidea KARG (Acarina, Parasitiformes), Zool.    Jb. Syst. 116, pp 31-46.-   Messelink, G. & Steenpaal, S. 2003, Nieuwe roofmijten tegen trips in    komkommer. Groenten & Fruit 43: 34-35.-   Messelink, G. 2004, Nieuwe roofmijt wint met overmacht in komkommer.    Groenten & Fruit 35: 22-23.-   Messelink, G. & Pijnakker, J. 2004, Roofmijten bestrijden    wittevlieg. Vakblad voor de Bloemisterij 43: 62.-   Messelink, G. & Steenpaal, S. 2004, Roofmijt nu ook kaswittevlieg de    baas. Groenten & Fruit 45: 26-27.-   McMurtry, J. A. and CroftB. A., 1997, Life-styles of phytoseiid    mites and their role in biological control, Annual Review of    Entomology, Vol. 42: 291-321.-   Nomikou, M., Janssen, A., Schraag, R. and Sabelis, M. W., 2001,    Phytoseiid predators as biological control agents for Bemisia    tabaci. Exp. Appl. Acarol. 25: 270-290-   Parkinson, C. L., 1992, “Culturing free-living astigmatid mites.”    Arachnida: Proceedings of a one day symposium on spiders and their    allies held on Saturday 21 Nov. 1987 at the Zoological Society of    London, eds. Cooper, J. E., Pearce-Kelly, P, Williams, D. L., p.    62-70.-   Ramakers, P. M. J. and Van Lieburg, M. J., 1982, Start of commercial    production and introduction of Amblyseius mckenzei Sch. & Pr.    (Acarina: Phytoseiidae) for the control of Thrips tabaci Lind.    (Thysanoptera: Thripidae) in glasshouses, Med. Fac. Landbouww.    Rijksuniv. Gent, 47/2, pp 541-545.-   Ramakers, P. M. J., 1989, Large scale introductions of Phytoseiid    predators to control thrips on cucumber, Med. Fac. Landbouww.    Rijksuniv. Gent, 54/3a, pp 923-929.-   Ramakers, P. M. J. and Voet, S. J. P., 1996, Introduction of    Amblyseius degenerans for thrips control in sweet peppers with    potted castor beans as banker plants. IOBC/WPRS working group on    integrated control in glasshouses 19(1): 127-130.-   Rasmy et al., 1987, A new diet for reproduction of two predaceous    mites Amblyseius gossipi and Agistemus exsertus (Acari:    Phytoseiidae, Stigmaeidae), Entomophaga 32(3), pp 277-280.-   Romeih, A. H. M., El-Saidy, E. M. A. and El Arnaouty, S. A., 2004,    Suitability Of Two Lepidopteran Eggs As Alternative Preys For    Rearing Some Predatory Mites. The first Arab Conference of Applied    Biological Pest Control, Cairo, Egypt, 5-7 Apr. 2004.-   Swirski, E., Amitai, S. and Dorzia, N., 1967, Laboratory studies on    the feeding, development and oviposition of the predaceous mite    Amblyseius rubini Swirksi and Amitai an Amblyseius swirskii    Athias-Henriot (Acarina:Phytoseiidae) on various kinds of food    substances. Israel J. Agric. Res. 17:101-119-   Sampson, C., 1998, The commercial development of an Amblyseius    cucumeris controlled release method for the control of Frankliniella    occidentalis in protected crops, The 1998 Brighton conference—Pests    & Diseases, 5B-4, pp 409-416.-   Solomon, M. E. and Cunnington, A. M., 1963, Rearing acaroid mites,    Agricultural Research Council, Pest Infestation Laboratory, Slough,    England, pp 399-403.-   Teich, Y. 1966, Mites of the family of Phytoseiidae as predators of    the tobacco whitefly, Bemisia tabaci Gennadius. Israel J. Agric.    Res. 16: 141-142.-   Wei-Lan Ma and J. E. Laing, 1973, Biology—of Amblyseius (Neoseiulus)    californicus, Entomophaga, 47-60.

The invention claimed is:
 1. A composition comprising: a rearingpopulation of a phytoseiid predatory mite species selected from thegroup consisting of the subfamily of the Ablyseiinae and the subfamilyof the Typhlodrominae, wherein mites from the subfamily of theAmblyseiinae are selected from the group consisting of a mite speciesfrom the genus Amblyseius, a mite species from the genus Euseius, themite species Neoseiulus califomicus, the mite species Neoseiulusfallacis, a mite species from the genus Typhlodromalus, and a mitespecies from the genus Typhlodromips, a factitious host population thatcomprises at least one species selected from the family of theGlycyiphagidae, and optionally a carrier for individuals of saidpopulations.
 2. The composition according to claim 1, further comprisinga food substance suitable for said factitious host population.
 3. Thecomposition according to claim 1, wherein the factitious host populationis a rearing population.
 4. The composition according to claim 1,wherein the number of individuals of the phytoseiid predatory mitespecies relative to the number of individuals of the factitious host isfrom about 100:1 to 1:20.
 5. The composition according to claim 1,wherein the factitious host species is selected from a subfamilyselected from the group consisting of: the subfamily Ctenoglyphinae; thesubfamily Glycyphaginae; the subfamily Aëroglyphinae; the subfamilyLabidophorinae; and the subfamily Nycteriglyphinae.
 6. The compositionaccording to claim 5, wherein the factitious host species is selectedfrom the subfamily Glycyphaginae.
 7. The composition according to claim6, wherein the factitious host species is selected from the genusGlycyphagus or the genus Lepidoglyphus.
 8. The composition according toclaim 7, wherein the factitious host species is selected from G.domesticus or L. destructor.
 9. The composition according to claim 1,further comprising a further nutritional source for the phytoseiid mite.10. The composition according to claim 9, wherein the nutritional sourceis pollen or a prey.
 11. The composition according to claim 10, whereinthe prey comprises a factitious host selected from the family of theCarpoglyphidae.
 12. The composition according to claim 1, wherein thephytoseiid mite is not Amblyseius swirskii.
 13. The compositionaccording to claim 1, wherein the phytoseiid predatory mite species is aspecies selected from the group consisting of: Amblyseius andersoni,Amblyseius swirskii, Amblyseius largoensis, Euseius finlandicus, Euseiushibisci, Euseius ovalis, Euseius victoriensis, Euseius stipulatus,Euseius scutalis, Euseius tularensis, Euseius addoensis, Euseiusconcordis, Euseius ho or Euseius citri, Neoseiulus californicus,Neoseiulus fallacis, Typhlodromalus limonicus, Typhlodromalus aripo,Typhlodromalus peregrinus, Typhlodromips montdorensis, Galendromusoccidentalis, Typhlodromus pyri, Typhlodromus doreenae and Typhlodromusathiasae.
 14. The composition according to claim 1, wherein thephytoseiid predatory mite species is selected from the genus Galendromusand the genus Typhlodromus.
 15. The composition according to claim 1,wherein the rearing population of a phytoseiid predatory mite specieshas a number of individuals that can grow by sexual reproduction by 50%or more in 7 days (T=25° C.; RH=80% feeding ad libidum).
 16. Method forrearing a phytoseiid predatory mite comprising: providing a compositionaccording to claim 1, allowing individuals of said phytoseiid predatorymite to prey on individuals of said factitious host population. 17.Method according to claim 16, wherein the composition is maintained at18-35° C. and/or 60-95% relative humidity.
 18. Method according to claim16, wherein said composition comprises a carrier and a suitable foodsubstance and the factitious host population is maintained as athree-dimensional culture on the carrier.
 19. Rearing system for rearinga phytoseiid predatory mite, which system comprises a container holdingthe composition according to claim
 1. 20. Rearing system according toclaim 19, wherein said container comprises an exit for at least onemobile life stage of the phytoseiid mite.
 21. Rearing system accordingto claim 20, wherein said exit is suitable for providing a sustainedrelease of said at least one mobile life stage.
 22. Method forbiological pest control in a crop comprising providing a compositionaccording to claim 1 to said crop.
 23. Method according to claim 22wherein the pest is selected from white flies, thrips, spider mites,tarsonemid mites, eriophyid mites, mealybug crawlers, and scalecrawlers.
 24. Method according to claim 22, wherein the composition isprovided by applying an amount of said composition to a number of cropplants.
 25. Method according to claim 24, wherein the amount is from1-10 ml, preferably 2-5 ml.
 26. Method according to claim 22, whereinthe composition is provided in the rearing system according to claim 20,by placing said rearing system among a number of crop plants.
 27. Methodaccording to claim 22, wherein the crop is selected from greenhousevegetable crops, greenhouse ornamental crops, tree crops or open fieldcrops.